Cystic Fibrosis

J Dowsett and O Tully, St Vincent's University Hospital, Dublin, Ireland

© 2005 Elsevier Ltd. All rights reserved.

Definition and Etiology

Cystic fibrosis (CF) is a multisystem autosomal recessive disorder caused by the mutation of a single gene on the long arm of chromosome 7 that codes for the cystic fibrosis transmembrane regulator (CFTR). This protein regulates the passage of chloride through the membrane of secretory epithelia; the dysfunction of which results in an altered composition of epithelial secretions. Clinically, CF is characterized by chronic pulmonary infection with periods of acute exacerbation, pancreatic insufficiency and excessive losses of sweat electrolytes. The latter forms the basis for the diagnostic test. The mutated gene was identified in 1989 and since then over 800 CFTR mutations have been reported, the most common of these being A F508.


Approximately 5% of the Caucasian North European and North American populations are carriers of the gene defect causing CF, leading to an approximate incidence of 1 in 2500 live births. This inheritance is illustrated in Figure 1. The incidence of CF in non-Caucasians is much lower and estimated to be around 1 in 100 000 in Oriental populations.



Supplements For Diabetics

Supplements For Diabetics

All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.

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